How to ensure that SSH is configured on the new node

Posted on 2013-05-16
Last Modified: 2013-05-29
Dear experts here:

I am going to add a new node to the oracle cluster. On this document:

step 4, it asked me to "Ensure that SSH is configured on the node". Then I use root account to ssh to the new node(poseidon) from an existing node(elysium). However, it gives me the following error. When I switch to "mis" user, I can SSH in without any problem. Could anybody help me to verify if the SSH is configured well. thank you.  

[root@elysium ~]# ssh poseidon
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
Please contact your system administrator.
Add correct host key in /root/.ssh/known_hosts to get rid of this message.
Offending key in /root/.ssh/known_hosts:3
RSA host key for poseidon has changed and you have requested strict checking.
Host key verification failed.
[root@elysium ~]#


[mis@elysium ~]$ ssh poseidon
mis@poseidon's password:
Last login: Thu May 16 15:22:32 2013 from
[mis@poseidon ~]$
Question by:Jason Yu
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
  • 2
LVL 21

Accepted Solution

Mazdajai earned 250 total points
ID: 39173235
Is it a reinstall or has the ip changed? If it is the case, remove line 3 on the file.

vi /root/.ssh/known_hosts

Open in new window

LVL 30

Assisted Solution

serialband earned 250 total points
ID: 39173519
sed -i '3d' ~/.ssh/know_hosts

Author Comment

by:Jason Yu
ID: 39182823
After I delete the third line in this file, it works now.

Connection to poseidon closed.
[root@elysium ~]# ssh poseidon
root@poseidon's password:
Last login: Mon May 20 15:27:05 2013 from
[root@poseidon ~]#

One more question, if I want to disregard the password (so I don't need to input password every time) which should I do?

Also, how to set up log in welcome logo. thank you.
Secure Your WordPress Site: 5 Essential Approaches

WordPress is the web's most popular CMS, but its dominance also makes it a target for attackers. Our eBook will show you how to:

Prevent costly exploits of core and plugin vulnerabilities
Repel automated attacks
Lock down your dashboard, secure your code, and protect your users

LVL 21

Assisted Solution

Mazdajai earned 250 total points
ID: 39182828
What type of distro? You need to setup key pair for passwordless login -

Open in new window

Not sure what you mean by "log in welcome logo"?
LVL 30

Assisted Solution

serialband earned 250 total points
ID: 39183369
Maybe you mean /etc/motd.  Put your text Message of the Day in the file and whenever you log in, it will be displayed.

Author Closing Comment

by:Jason Yu
ID: 39206339
thank you guys, got it solved satisfied.

Featured Post

Percona Monitoring and Management and Grafana

Proactive monitoring is vital to a highly-available environment. We have a quick start guide on Experts Exchange for Grafana users.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

I. Introduction There's an interesting discussion going on now in an Experts Exchange Group — Attachments with no extension ( This reminded me of questions tha…
In part one, we reviewed the prerequisites required for installing SQL Server vNext. In this part we will explore how to install Microsoft's SQL Server on Ubuntu 16.04.
Viewers will learn how to properly install and use Secure Shell (SSH) to work on projects or homework remotely. Download Secure Shell: Follow basic installation instructions: Open Secure Shell and use "Quick Connect" to enter credentials includi…
This demo shows you how to set up the containerized NetScaler CPX with NetScaler Management and Analytics System in a non-routable Mesos/Marathon environment for use with Micro-Services applications.
Suggested Courses

623 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question